1. Field of the Invention
The invention relates to nitrogen-containing reaction products and to their use in lubricant compositions. More particularly, the reaction products are made by reacting alkenylsuccinic anhydrides with an aminoalcohol and an aromatic secondary amine or phenol, the phenol having, in addition to the hindering groups, a hydroxyhydrocarbyl group.
2. Discussion of Previous Disclosures
It is known that in the normal use of organic industrial fluids, such as lubricating oils, transmission fluids, bearing lubricants, power transmitting fluids and the like, the base medium is subjected to oxidizing conditions which may result in the formation of sludge, lacquers, corrosive acids and the like. These products are undesirable in the equipment in which the industrial fluid is used. The oxidation residues or heavy contaminants may interfere with the normal operation of the fluid, increase its viscosity, and even cause severe damage to the parts of the equipment themselves.
In the lubrication of modern engines, particularly, oil compositions must be able to prevent acids, sludge and other solid contaminants from remaining near the moving metal parts. Poor piston travel and excessive engine bearing corrosion may result, unless the oil can prevent the sludge and oxidation products from depositing in the engine. Bearing corrosion is another serious problem in gasoline engines which operate at an oil temperature of about 300.degree. F. or higher.
The most desirable way of decreasing these difficulties is to add to the base organic fluid a detergent or dispersant additive capable of dispersing the solid particles to prevent them from interfering with the normal operation of the equipment, and leaving the metal surfaces relatively clean. Today, with modern equipment operating under increasingly strenuous conditions, it is desirable to develop new detergents which have improved dispersant properties, which are soluble in the fluid medium to which they are added, and which are themselves stable therein.
U.S. Pat. No. 3,714,045 discloses lubricant compositions containing lubricants and a polyimide produced by reacting (1) a heteropolymer produced by reacting an olefin with moleic anhydride in the presence of a free-radical initiator with (2) a primary arylamine.
U.S. Pat. No. 3,936,480 discloses the reaction of a polyalkylenesuccinic acid anhydride with diphenylolpropane of the formula ##STR1## and tetraethylenepentamine, pyridine or triethylenetetramine. It should be noted however, that in all cases wherein diphenolpropane is reacted, a catalyst is used. This is an absolute necessity when a phenolic OH is present, because there will be no reaction with the anhydride without it.